Many patients who have undergone surgical procedures such as
laminectomies to treat back pain and radiculopathy continue to experience
pain postoperatively or redevelop pain at a later date. These patients
may, in some cases, undergo one or more repeat operations to further
treat their pain. Despite surgical interventions, a percentage of
these patients will continue to be plagued by pain. When surgically
remediable anatomic lesions such as herniated disks, spinal stenosis,
or a suboptimal fusion have been corrected, patients may be considered
for placement of a spinal cord stimulator. In addition to pain relief,
outcome measures such as decreased use of analgesics, increased
physical activity, loss of neurologic function, and return of the
previously disabled to work have been examined in a number of studies.18–20 These
studies showed that patients who derived pain relief from spinal
cord stimulation often diminished their analgesic use or discontinued
it altogether. Additionally, most were be able to perform more routine
daily activities, and some who had previously been unfit to work
were able to gain employment. Another study has been performed to
compare outcomes when patients with failed back surgery syndrome
were treated with spinal cord stimulation versus re-operation.21 In
an initial series of patients, the rate of crossover from re-operation
to placement of a spinal cord stimulator was much greater than the
reverse. These initial results suggest that, in some patients with
failed back surgery syndrome and surgically correctable lesions,
spinal cord stimulation may serve as a viable alternative to re-operation
in further treating pain. Traditionally, pain in a monoradicular
distribution has been the most amenable to treatment by neurostimulation.
With larger areas of pain, it is more difficult to adequately cover
all of the pain with paresthesias, a necessary prerequisite for
success in using neurostimulation. Therefore, patients with more
complex pain patterns, such as bilateral radiculopathy with axial
low back pain, have often been seen as less apt to respond to spinal
cord stimulation. As the technology becomes more advanced, with the
use of multielectrode, multichannel, and multiprogram devices, these
more complex pain patterns are increasingly being viewed as responsive
to spinal cord stimulation.22–26